Generally, an ink jet recording head employed in an ink jet recording apparatus includes an ink jet recording head for forming a droplet of ink or the like and a supply system that supplies the ink or the like to this recording head.
As for connection between a liquid discharge substrate adapted to this recording head and a wiring member, a wide array ink jet device configured by a print head substrate having electric connection electrodes formed on an opposite surface to a surface on which a discharge port is formed is disclosed in Japanese Patent Application Laid-Open No. 11-192705. FIGS. 17 and 18 show a wide array ink jet pen 210 described in Japanese Patent Application Laid-Open No. 11-192705. FIG. 17 is a perspective view of the wide array ink jet pen including a wide array print head. FIG. 18 is a partial sectional view of print head dies and a support substrate 220 for showing an electric connection portion of the wide array ink jet print head shown in FIG. 17. The pen 210 includes a wide array print head 212 and a pen main body 214. The pen main body 214 is a housing to which the print head 212 is attached. The pen main body 214 includes an internal chamber 216 that acts as a local ink tank. Referring to FIGS. 17 and 18, the print head 212 includes a plurality of print heads 218 attached onto the support substrate 220. An electrode 284 for electrical connection and an ink supply port 242 are formed on a back surface of each print head 218 opposite to a surface on which a nozzle opening 238 is formed. Electric wirings are formed on a first surface 270 and a second surface 272 of the support head 220 for holding the print heads 218, respectively. The support substrate 220 is arranged to be electrically connected to the print heads 218 by solder bumps on the first surface 270 thereof, respectively. A logic circuit (not shown) and a driver circuit 230 are mounted on the second surface 217 of the substrate 220 opposite to the first surface 270.
The ink jet recording head configured so that the liquid discharge substrates include the ink supply ports formed on the back surfaces thereof opposite to the surfaces on which the nozzle openings are formed, includes connection electrodes for the electrical connection to the other members provided near the nozzle openings, and are electrically connected to the surface of the support substrate on which the electrical wiring is formed as stated above has the following disadvantages.
For example, in the ink jet recording head shown in FIG. 18, the ink supply port formed in the support substrate and that formed in the liquid discharge substrate should communicate with each other. Specifically, it is necessary to form a partition wall that ensures separating the liquid, around the ink supply ports to thereby completely prevent entry of the ink into the electrical connection portion and to also completely prevent leakage of the ink to the outside.
To do so, it is important to ensure high opening dimension accuracy and high position accuracy of the ink supply ports of the liquid discharge substrate and the support substrate.
In the head disclosed in the Japanese Patent Application Laid-Open No. 11-192705, the support substrate 220 is formed out of such a plate member including silicon, multilayer ceramic, or glass epoxy resin and having a substantial thickness as that used when forming a hybrid multi-chip module.
The support substrate 220 is, therefore, inferior in workability and the opening position accuracy and the opening dimension accuracy of the ink supply port 242 are not so high. As a result, the ink supply port of the support substrate 220 tends to be relatively misaligned to the ink supply port of the liquid discharge substrate. This disadvantage is conspicuous particularly if an adhesive or a sealing agent is used in the liquid partition wall of each ink supply port. With this configuration, the position of the adhesive and the sealing agent is greatly influenced by that of an end surface of the ink supply port of the support substrate. As a result, if the position of the end surface of the ink supply port of the support substrate overlaps with that of the ink supply port of the liquid discharge substrate, the adhesive or sealing agent disadvantageously flows into the ink supply port of the liquid discharge substrate. Besides, in the ink jet head, a desire to arrange a plurality of liquid discharge substrates as narrow as possible at high density from viewpoints of cost and size rises. Accordingly, it is also necessary to form the ink supply port of the support substrate as narrow as possible at high density. However, the support substrate disclosed in FIG. 18 has sufficiently large thickness, with the result it is difficult to form the narrow ink supply port with high accuracy.